Main Characters Astrophysicist 152 main appearances Narrator 126 main appearances Astronomer 94 main appearances Astronomer, NASA Goddard Space Flight Center 72 main appearances Planetary Scientist 27 main appearances Planetary Protection Engineer 33 main appearances Astrophysicist / Planetary Scientist, Southwest Research Institute 33 main appearances Cosmologist / Theoretical Physicist, Arizona State University 28 main appearances Planetary Scientist and Geologist 26 main appearances Theoretical Physicist, City University of New York 15 main appearances
Recurring Guest Characters Volcanologist 1 guest appearances Advanced Propulsion Technologist 1 guest appearances Astronaut 1 guest appearances Biomedical Scientist 1 guest appearances Phd., Physics and Astronomy 1 guest appearances Assistant Professor of Planetary Science 1 guest appearances New Horizons Principal Investigator 1 guest appearances Geochemist 1 guest appearances Messenger Principal Investigator 1 guest appearances Evolutionary Biologist 1 guest appearances Juno Principal Investigator 1 guest appearances Space Scientist 1 guest appearances Co-lead investigator for the Double Asteroid Redirection Test (DART) 1 guest appearances Astronomer (archive footage) 1 guest appearances Data Scientist 1 guest appearances Rosetta Scientist 1 guest appearances Voyager Imaging Team Member, 1988 - 1989 1 guest appearances Voyager Scientist, 1977 - 1990 1 guest appearances Director, Center for NEO Studies 1 guest appearances NEO Observations Program Manager 1 guest appearances ⇤ « 1 2 3 » ⇥